Process and apparatus for making balls and improved balls



y 1945- G, s. RADFORD ET AL 2,376,085

PROCESS AND. APPARATUS FOR MAKING BALLS AND IMPROVED BALLS Filed Oct.11, 1959 2 Sheets-Sheet l A I gmmuu% Ef wan;

y 1945-. G. s. RADFORD ET AL 2,376,085

PROCESS AND APPARATUS FOR MAKING BALLS AND IMPROVED BALLS Filed Oct. 11,1959 2 Sheets-Sheet 2 INVENTORS Patented May 15, 1945' rnocnss ANDAPPARATUS FOR .MAKING BALLS AND nuraovnn BALLS v George S. Radford, NewCanaan, Conn., and Anthony Couture, Springfield, Mass., assignors to A.G. Spalding & Bros. Inc., New York, N. Y a corporation of Delaware IApplication October 11, 1939, Serial No. 298,914

7 Claims.

This invention relates to improvements in molding apparatus, to animproved method of molding covers on bodies, and to improved articl'es.

Although the present invention is applicable to divers objects, it isespecially advantageous in molding a spherical cover on balls, such asgolf balls.

Heretofore, it has been the most usual practice to form covers on golfballs by first making a spherical body and then enveloping the same withtwo originally separate hemispherical cuplike member which in turn wereforced and shaped upon the spherical body. However, this in effectresulted in a considerable manufacturing cost because: (1) the twoseparate cuplike members would have to be made for each ball; (2) thecup halves would have to be carefully assembled to the spherical body;(3) the assembly including the spherical body and the two cup halveswould have to be carefully placed in a die and there pressed and moldedupon the spherical body; (4) a flash line would have to be removed fromthe finished ball; and, (5) this old and usual practice had the furtherdisadvantages of causing the internal spherical body to be ofi center ifeither one of the two cup halves happened to be thicker than the other.

Also, some of these old ways of covering balls required a lengthy timefor vulcanization in the mold, which, especially if the materialhappened to be soft, or become soft in the heated moldin die, allowedthe ball to settle by gravity within the covering material so that itwould finish offcenter. The flash, in the old methods, if heavy, andstarting to flow from one side of the die, also had a tendency to pullthe center to one side of the die.

It is an important object of the present invention to provide animproved method and apparatus for covering spherical bodies; such asgolf and other balls, in an economical manner.

A feature resulting from the attainment of this object includes theprovision of a simple apparatus whereby it is possible to firstpartially cover the ball and then to completely cover the remainder ofthe ball in two simple steps.

A complemental feature of the present invention is the provision of asimple apparatus for first molding one half of the cover thereon andthen molding the remaining half.

A further feature is the provision of an apparatus capable of forming apartial cover and locator section, or sections, on a spherical body andfor efiiciently enveloping the remainder of the body with a cover.

It is another object of the present invention to provide apparatuscapable of molding a cover of uniform thickness completely around aspherical body.

The feature of the present invention resulting from the attainment ofthis objective includes the provision of an apparatus capable ofaccurately locating a spherical body centrally relative to a die part orparts which shape the exterior of the cover.

It is still a further object of the present invention to provide ahighly satisfactory covered object, such as a golf and other ball, inwhich the cover is of uniform thickness, and is economically formedthereon.

It is a further important object of the present invention to provide animproved method for covering spherical bodies which will insure a largedaily production with a product of uniformly high quality.

A feature of this invention is the teaching of a method of first forminga partial cover on a spherical body of a given thickness andsubsequently forming the remainder of the body of substantially the samethickness as the part of the cover first formed.

Features of the invention include the provision of: a novel apparatusfor injection molding covers on divers objects, and particularly balls;a novel method of injection molding covers on divers objects; and,products, such as balls, with a cover injection molded thereonuniformly, and economically.

Other objects, features, and advantages will appear hereinafter.

In the drawings:

Figure 1 is a cross-sectional view of one form of die for molding partof the cover on a spherical body.

Fig. 2 is a cross-sectional view, similar to Fig. 1, showing the die formolding the remainder of the cover.

Fig. 2A is a fragmentary sectional view showing the inner face of thecavity in the upper die.

Fig. 3 is a sectional view of a modified form of die.

Fig. 4 is a fragmentary sectional view of a still further modified formof die.

Fig. 4A is a fragmentary section view showing a modified form of dieandbonding joint.

Fig. 5 is a fragmentary sectional view of an apparatus for moldingbuttons upon a spherical body.

Fig. 6 is a sectional view of an apparatus for molding the remainder ofa cover on spherical bodies which have protuberances or locator buttonsor the like thereon.

Fig. '7 is a detailed view of a locator band.

Fig. 8 is a detailed view of a ball with a plurality of locator bands inplace.

Fig. 9 is a view showing a modified form of locator band.

Before describing the present improvements and mode of operation thereofin detail it should be understood that the invention is not limited tothe details of construction and arrangement of parts shown in theaccompanying drawings, which are merely illustrative of the presentpreferred embodiments, and the phraseology employed is for the purposeof description and not of limitation.

Referring in detail to the drawings which disclose the present preferredembodiments of the invention, and to Figs. 1-4, inclusive, first, theapparatus of the present invention discloses a complete die It!including a first or lower die ll having a locator cavity I2 adapted toreceive a spherical body l3. This cavity is preferably of the samediameter as the spherical body. Cooperating with the first or lower dieII is a second or upper die M. This second die is provided with amolding cavity P5 of larger diameter than the locator cavity l2. Thespace between the cavity I5 and the periphery of the spherical body,while the latter is in the locator cavity, is proportioned to form acover "5 of the desired thickness. The upper and lower dies l4 and H,respectively, of Fig. 1, maybe located in relation to each other as byshoulders I1.

The molding die l may be placed in an conventional molding press inorder to locate the upper and lower dies l4 and II relative to eachother and to move the upper die l4 into and out of operative engagementwith the lower die H. Even a simple arbor press may be used for thispurpose. Since there are many forms of apparatus for this purpose, onlya ram l8 and die base l9 have been shown herein, in order to simplify anunderstanding of the invention.

The upper die I4 is provided with a duct 20 conducting any suitableplastic material to the cavity l and for filling the space between theexposed periphery 2| of the spherical body l3 and the inside face 22 ofthe cavity l5. As shown, partially by cross-sectional lines in Fig. 1.the duct 20 is preferably surrounded by a suitable heating means such asan enclosed electric heat coil 41, to keep the plastic material in theduct warm and in a semifiuid state until it is injected into the cavity.Any of the now well-known machines for storin and injecting a plasticmaterial may be used to force material through the duct 20 into thecavity l5.

Normally the die I0 is cold enough to congeal or set this plasticmaterial when the cavity I5 has been filled. However, if preferred, achamber 23 may be provided in the upper half Hi to heat and/or cool thedie in any usual way, or in the manner set forth hereinafter inconnection with Fig. 6. For example, if the plastic materialis very hotand a large number of covers formed on balls in the cavity IS in rapidsuccession, to prevent the die from overheating and insure separation ofthe cover from the die, a continuous flow of cold or cool water may bepassed through the chamber; and, if the plastic material must be givenextra heat for a period of time and then cooled, both heating andcooling mediums may be passed through the chamber 23. A suitable airvent 24 is provided to clear air'from the cavity l5 as the plasticmaterial 25 is injected therein to form the locator and half cover 26,shown in Fig. 1.

The apparatus for completely covering the ball includes a secondarylower'die 21 as shown in Fig. 2 which is provided with a large cavity 29of the same diameter or configuration as the cavity l5 of the upper dieM (or just slightly smaller to allow for the congealing or shrinking ofthe locator and half cover 26) so that it will accommodate the moldedhalf cover 26 formed on the spherical body I3 as shown in Fig. 1. Whenthe spherical body with a half cover is set in the secondary lower die21, the upper die I4 is merely superimposed thereon and a second halfcover 29 is molded on the spherical body in the same manner as the firsthalf cover, as clearly shown in Fig. 2, by injecting plastic material,through the duct 20 to provide a complete cover I6.

With this apparatus just described in detail, it is possible to form twohalf covers 26 and 29 on the ball, each of which is of uniformthickness. The two halves are satisfactorily united where they cometogether, as shown by crosshatching in Fig. 2, through a regularamalgamation or bonding of the edge 30 with the edge section 3| of thehalf cover 29 while the latter is still semiplastic or has not yetcongealed greatly.

To further insure a proper bonding of the two half covers 26 and 29, aspecial coil 32 can be provided extending completely around the die 21near the middle, which in turn through a conduit 33 and two-way valve 34may alternately be connected to a conduit extending to a source of steamfor heating and through a conduit 35 to a source of cold water to set orcongeal the joint 36.

If preferred, the die ll of Fig. 1 may be made somewhat differently likethe lower die 37 shown in Fig. 3 so that it has the large cavity 28acorresponding substantially with the cavity of Fig. 2 and may beprovided with a liner 38 with a cavity l2a like the cavity l2 of Fig. 1.Thus, it is merely necessary to allow the liner 38 to be in the lowerdie 31 when the half cover 26 of Fig. 1 is formed and merely remove theliner 38 in order to nest the spherical body l3 with the locator andhalf cover 26 therein to form the remaining half cover 29. To do thelatter it is merely necessary to move the spherical body l3 with thehalf cover 26 approximately 180 from the position shown in Fig. 1 to theposition shown in Fig. 2 after the liner has been removed. The liner 38may be held in place as by a screw 39 if preferred.

Fig. 4 discloses a further slightly modified form of the presentinvention differing from the form described primarily in the provisionof an angular lip 40 on the lower die Ha of substantially the same widthas the lower edge 30 of the half cover 26 to form an angular edge 4|.This angular lip may be formed on the lower die it of I Fig. 1 or may beprovided at the upper side of the liner 38 shown in Fig. 3. Preferably,it is provided upon a liner 38a, shown in Fig. 4A, similar to the liner38 of Fig. 3, so that serrations i2 may also be provided thereon toincrease the area of bonding, and the strength of the bond when thesecond half cover 29 is molded thereon.

The spherical body l3 with the half cover 26 surface of the center I3.

Any suitable and usual injection apparatus may be used to force theplastic material 25 through the duct 20 to the space between the cavityl of the upper die l4 and that portion of the spherical body l3 notnesting in the lower die II when the first section of the cover ismolded (viz., when the locator and half cover 26 are molded to thespherical body l3). The duct is preferably flexible so that the ram l8with the upper die l4 may be reciprocated.

An air vent, such as the vent 24, may be provided to clear air from thedie and allow the plastic material to be freely injected therein. Ifpreferred, the air vent may be in the form of a small channel along thefaces 43 and 44 of the upper die so that plastic material forced thereinis cleared from the die easily when the 'ball and cover are removedtherefrom.

Also, the cavity |5 may, as shown fragmentarily in Fig. 2A, be providedwith protuberances 45 or the like to form dimples in the outer surfaceof the ball.

.Referring now to Figs. 5-9, inclusive, there is disclosed a modifiedform of the present inven-- tion. comprising a molding die including anupper die 5| and lower die 52. Preferably both dies 5| and 52 areprovided with cavities 53 and 54 respectively adapted to receive thecenter I3 of the ball and are also provided with recesses 55 and 58 forforming buttons 51 upon the outer recesses, and the shape thereof, issuch that the draft or draw of the center l3 with the buttons 51 fromthe die may be accomplished very easily.

Referring in greater detail to the die 50 and the parts thereof, it willbe noted that the die includes reservoirs 58 and 59 for housing suitableplastic material 68 known as cover stock and usually comprising arubbery mixture. Each of these reservoirs 58 and 59 is backed byplungers 6| and 82, respectively, for forcing the plastic compositionthrough orifices 63 and 64 into the button-forming cavities 55 and 56.Any suitable apparatus may be provided for clamping the die halves 5|and 52 together, and to move the plungers 6| and 62 compressively. Forexample, any usual and well-known double-ended and double-actinghydraulic press may be provided for the purpose. 7

In order to sever the buttons 58 from the orifices 63 and t l thepresent invention provides a lever 65 pivoted on a stud 66 with a pin 61entering suitable elongated apertures in fingers 68. If the lever $5 ispivotally moved, for example by grasping and pushing the handle 69, theentire spherical center I3 with buttons 51 thereon are moved free andclear of the orifices 63 and 64. As the buttons 51 in the cavities 55and 56 move clear of the orifices 68' and 64 the rear walls 18 and H ofthe dies 5| and 52 serve to close the orifices.

The reservoirs 58 and 59 may be heated in any suitable way to keepplastic composition 60 therein in a fluid or plastic state. For example,electrical heating coils 12 may be provided as shown in Fig. 5. Becausethe button-forming recesses 55 and 56 are very small compared to thereservoirs 58 and 59, the plastic material 68 congeals and hardenssufficiently without the aid of a cooling apparatus. This lattercongealing or hardening is also .promoted by the cooling exposure of thedie cavities 53 and 54 to the surrounding atmosphere when successivecores i3 with the buttons 51 thereon are removed from the die.

The location of these After the centers I3 are provided with buttons 51as illustrated in Fig. 5, and as just described, they are placed in asecondary molding die 13 as shown in Fig. 6. The previously molded orformed buttons 51 thereon serve to centralize and space the core l3 fromthe walls 14 and 15 of cavities 16 and 11. The upper and lower dies 18and 19 are located relative to each other as by the depending flange 88of the upper die and the upstanding flange 8| of the lower dierespectively, and also by a ram 82 and die bed 83 of an arbor or anyother usual press. They may be locked or held together against verticaldisplacement by any suitable means.

The walls 14 and 15 may be provided with a series of round projections84 or any other desired configuration to impart the desired surfacecharacteristics to the ball.

Each of the die halves 18 and 19 is connected to a reservoir of plasticmolding composition 85 as by conduits 88 and 81. Preferably theseconduits are surrounded by heating means such as the electrical coils88. These conduits are preferably flexible in order to permit separationof the of cool water or other cooling medium through the conduit 91.Outlet conduits 98 and 99 are also provided to release or take off theheating and cooling medium during alternate changes. Any of the suitableand well-known heating and cooling arrangements may be provided in placethereof.

Normally. intermittent exposure-of the cavit'es 16 and 1 1 keep the diescool enough to congeal or set the plastic material therein. However, ifpreferred, heating nd/or cooling of the secondary d e 13, and be h theupper and/or lower parts thereof, may be effected as by providingsuitable chambers 89 and 98 therein, having connections 9| and 92 tosources of steam or hot water and to a cool water. For example, toinsure a continually cool die cold water may be forced through thechambers 99 and while successive covers are molded upon centers.

After the center i3 with buttons 51- is placed in the secondary die '33and the two die halves wand 19 brought together the plastic composition85 is forced through the conduits 8t and 81 by any of the well-knowninjection molding machines in order to build up a complete covering onthe center as shown in general in Fig. 6. The pressure Wth which thiscovering composition is forced therein is usually sufiicient to effeet agood adherence and amalgamation with the previously molded buttons, sothat the buttons and the subsequently molded cover are substantiallyintegral. To further insure the proper amalgamation between the buttonsand the subsequently molded sections of the cover the centers withbuttons may be moved immediately from the first or primary molding d e,and while the buttons are still warm and semiplastic, into the secondarymolding die. Congealing of the plastic material molded thereon in thedie of Fig. 6 tends to tighten upon the buttons til. Further, becausethe buttons are tapered as they extend toward the outer surface of thecover the plastic material applied in the die of Fig. 6 tends to lockthem to the center I3.

Any suitable air vent, such as the vent 24 of Fig. 1, may be provided inthe dies of Figs. 5 and 6, as will be readily appreciated. Conduits 93and 98 are flexible so that the dies I8 and I8 1 maybe moved togetherand apart.

After the secondary molding, in the die of Fig. 6, the dies 18 and I9are separated whereupon the covered object may be removed.

The cover material congeals or shrinks slightly during the cooling sothat removal is easily accomplished. If any slight tip remains on thecover at the point where the same extends into the apertures I and IMthe same may be easily removed.

If preferred the molding of buttons 51 on the core I3 may be dispensedwith by merely wrapping bands I02 with uniform buttons I03 onto the coreI3, as shown in Figs. '7 and 8. Such bands may be easily andeconomicallymolded in large quantities. Alternatively, and even more economically,as shown in Fig. 9, the bands may be extruded in the form of an endlesstube I04 with endless ribs or projections I05 thereon,

which when cut to short lengths form narrowbands I04a with buttons I050.thereon. A pair of the latter may be snapped upon a core l3 similarly tothe bands I02 shown in Fi 8.

Thereafter cores I3 with either the bands I04a or I02 are dropped intothe cavity 11 of the die I9 shown in Fig. 6 and the upper die I8 closedthereon in order to form or mold the secondary cover thereon, all in themanner as hereinbefore described.

. From the foregoing it will be apparent that: the first cover 26 ofthat form of the invention shown in Figs. 1 and 2; the buttons 51 moldedto the core as shown in Figs. 5 and 6; and, the buttons I03 or I05aapplied thereto, all serve as locators to centralize the object to becovered,

such as a ball center, relative to the die for the secondary molding.

The method provided by the present invention includes the steps of:making a suitable core, ball center, or the like; providing locators andpartial covers on the core; and forming a secondary or complementarycover therefor.

A further specific method Of the present invention consists in the stepsof forming a core, ball center, or the like; molding at least one 10-cator and partial cover on the core, ball center, or the like;centralizing or otherwise locating the core, ball center, or the like ina die with said molded locator and partial cover; and then molding theremainder of a cover on the same. To

further insure a good connection between the partial cover first appliedto the core, ball center, or the like and the secondary cover, or tohave the secondary cover more effectively hold the partial cover firstapplied, the method consists in: making a core, ball center, or thelike; forming and applying, at least one locator and partial cover tothe same with an angular wall or walls; and molding a secondary andcomplementary cover on the same which locks with the angular walls onthe first or partial cover.

The bands I02 and IBM may be made of any suitable material. Preferablythey are made of substantially the same material as the materialinjected in the die I3 of Fig. 6, and preferably such that it melts orotherwise amalgamates and fluxes with the material forming the secondarycover I06.

The molding material may be in a plastic or a semifluid condition wheninjected into the foregoing dies, or may be in a granule or pulverizedstate when injected. With the former separate heating and cooling mayusually be dispensed with, and with the latter heating and cooling ispreferably used.

The serrations 42 may be extended radially on the angular lip 40 insteadof circumferentially as shown in Fig. 4A.

A further, and preferred, modification of the present invention includesmerely a combining of those forms of the invention shown in Figs. 1 and2 in a conventional reciprocating two-way press or in a conventionalrotary indexing or dialing press structure.

More particularly, and for example, the die bed I9 may carry both theprimary lower die II and the secondary lower die 27, and may have asuitable dovetail sliding connection with a base IIO so that first thedie II is brought into position below the ram I8 and die I4 and then thesecondary die 21. A suitable locator III may be used to accuratelyposition and hold the dies II and 21 below the ram I8.

Thus, the die II is first positioned below the ram I8 and die I4 to formthe half cover 26, whereupon the ram I8 and die I4 with the half cover26 are raised relative to lower die Ii, and the locator III releaseduntil the secondary die 21 is positioned centrally under the ram I8,whereupon plastic material is injected through the conduit I I2 to formthe lower half cover 26.

The apparatus may be of the multicavity type; e. g., may contain aplurality of rams I8 and the bed I8 may be an index plate carrying aplurality of primary and secondary dies II and 2? respectively. Also theone ram may be provided with a plurality of dies I I. The secondary die21 may also be provided with a heating and cooling chamber connected tosuitable sources of heating and cooling mediums as described inconnection with the chamber 23 shown in Fig. 1. Use of air vents, suchas 24, may usually be dispensed with.

If preferred the ram I8 and the bed I 0 may both be carried on a largeswivel plate, pivoted on a suitable upright or standard, whereby it ispossible to move the same through an arc of approximately so that thedie I4 with the first half cover will be at the bottom when the secondhalf cover is molded thereon. Conventional knockout pins for moldingdies may be provided.

Other variations and modifications may be made within the scope of thisinvention and portions of the improvements may be used without others.

Having thus described the invention what is claimed as new is:

1. The method of making balls consisting in the steps of forming aspherical body; forming a plurality of generally opposed buttons on saidbody to partially form a cover; and subsequently forming the remainderof a cover on said spherical body.

2. The method of making balls consisting in the steps of forming aspherical body; placing at least one band with protuberances on saidbody, to partially form a cover therefor; placing said body and band ina die, with the protuberances engaging the die to centralizethespherical body therein; and subsequently molding the remainder of thecover on the body.

3. In an apparatus for covering spherical bodies the combination of afirst large half die; a

liner for converting said large half die into a small half die adaptedto locate and support the spherical body; a second large half die; meansfor injection molding material between the spherical body and the largesecond half die while the spherical body is in the liner and first halfdie; and means for subsequently forming the remainder of the coveron-the body when the liner is removed and the initially molded coveredpart is in the first half die without the liner,

4. In an apparatus for covering a spherical body the combination of anupper die with a cylinder for plastic material; a lower die with acylinder for plastic material; nestingmechanism in said upper and lowerdies for closely and positively nesting said spherical body againstupward, downward and sidewise movement relative to the upper and lowerdies; said nesting mechanism including molding means associated with atleast one of said dies for forming spherical body locating means and apartial cover around the spherical body; and means for forcing plasticmaterial from said cylinders to said molding means.

5. The method which consists in the steps of forming a concentricspherical body, with a uniform circular surface; molding a plurality ofgenerally opposed buttons on said spherical body with end faces, topartially form a cover; and subsequently forming the remainder of acover on said spherical body, with an outer face coextensive,circular'and concentric with the outer faces on the plurality ofbuttons.

tainer to said molding means.

7. In an apparatus of the class described the combination of a moldingdie with a wall formation defining a cavity for receiving a sphericalbody and having an outer wall surface, said wall formation having aplurality of button defining recesses extending therethrough from saidouter wall surface and facing said cavity; means having an inner surfaceopposed and complementary to said outer wall surface for receiving saiddie for turning movement therein, said means having passage therein fordirecting plastic material to said recesses; means for forcing plasticmaterial through said passages into said recesses to mold buttons onsaid body; and means for turning said die relative to said first-namedmeans whereby said buttons are severed from the plastic material in saidpassages and said passages are closed by said outer wall surface.

GEORGE S. RADFORD.

ANTHONY COUTURE.

